Gal d 7 - a major chicken meat allergen
Published online: March 17, 2020
Poultry meat is recommended as an essential part of a healthy diet due to its relatively low amount of fat and the presence of high-quality proteins, vitamins and important micronutrients. The worldwide consumption of poultry meat has increased almost three-fold in the last 50 years. However, meat of chicken and other poultry can also induce severe IgE-mediated allergic reactions. So far, reliable data on the prevalence of poultry meat allergy are not yet available and the molecules causing poultry meat allergy are still largely unknown.
In a recent study published in The Journal of Allergy and Clinical Immunology (JACI) Klug et al. analyzed the IgE reactivity profiles to raw and cooked chicken muscle in a large cohort of well-characterized chicken meat allergic individuals. Peptide mass fingerprinting, an analytical technique for protein identification, allowed the authors to identify an IgE-binding protein of a molecular weight of 23 kDa, recognized by the majority of patients, as the muscle protein myosin light chain 1 (designated Gal d 7). Recombinant Gal d 7 (rGal d 7) was produced in a bacterial expression system and the molecule’s structure, thermal and enzymatic stability as well as its IgE binding capacity and cross-reactivity with allergens of other poultry species were assessed.
The authors saw that rGal d 7 represents a properly folded protein with IgE binding capacity comparable to its natural counterpart. IgE reactivity analysis in 28 chicken meat allergic patients revealed that Gal d 7 represents a major allergen for patients primarily sensitized to chicken meat. Furthermore, the authors also detected Gal d 7 cross-reactive allergens in other poultry species, such as turkey, goose or duck, and saw that rGal d 7 contains the majority of IgE binding epitopes present in the related molecules. These findings suggest that rGal d 7 can be used as a diagnostic marker allergen for genuine poultry meat allergy. The authors further observed high thermal stability, refolding capacity and resistance to salivary and gastrointestinal enzymes, which might explain why Gal d 7 can act as a potent sensitizing agent for poultry meat allergic individuals.
The authors identified myosin light chain 1, designated Gal d 7, as a novel major chicken meat allergen. Recombinant Gal d 7, produced in this study, represents a tool that can be used to identify patients with primary sensitization to poultry meat. The molecule will certainly help to get a better understanding of the phenomenon of poultry meat allergy.
The Journal of Allergy and Clinical Immunology (JACI) is an official scientific journal of the AAAAI, and is the most-cited journal in the field of allergy and clinical immunology.
Graphical Abstract